Post-Tropical Arthur now in Maritime Canada

Partially analyzed RGB satellite imagery with Arthur and Bermuda marked with respect to a front.

Hurricane Arthur brought tropical storm conditions to Nantucket, Martha’s Vineyard, and isolated spots on Cape Cod late last night and early this morning – along with torrential rain that led to some flash flooding in southeastern Massachusetts. A cold front associated with the deep layer trough responsible for Arthur’s steering northeastward became stationary and Arthur tracked parallel to it, increasing convergence and shower activity along the front. Later this morning, Arthur weakened below hurricane strength, became post-tropical, and then made landfall in Nova Scotia with 70mph sustained winds and New Brunswick with 65mph sustained winds. Eastern Maine, New Brunswick, Quebec, Nova Scotia, and Prince Edward’s Island have experienced tropical storm (gale) conditions from now Post-tropical storm Arthur.

Widespread gales are diminishing over Maritime Canada as Arthur continues to weaken, but widespread heavy rains and scattered severe gusts are still occurring around the center of the storm. Arthur is expected to continue to head northeastward through Maritime Canada and into the Labrador sea, nearing Greenland by mid-week as a post-tropical storm.

Post-tropical Storm Arthur is dragging a cold front and troughiness across the western Atlantic and it is nearing Bermuda. Some isolated showers have been observed this evening ahead of that cold front. This front is expected to move near Bermuda and become stationary overnight tonight into tomorrow morning keeping isolated to scattered showers nearby with a chance for thunder. Bermuda-Azores high pressure begins to take over again early next week and the stationary front dissipates nearby with a lingering chance for showers.

For the latest official information on Arthur see the Canadian Hurricane Center (who have taken responsibility for advisories when Arthur became post-tropical). For the latest official information on future tropical cyclones in the Atlantic see the National Hurricane Center. And, for the latest official information regarding Bermuda, see the Bermuda Weather Service.

Recap, below are a series of Google Earth images with Arthur’s track, and preliminary peak gusts (mph) overlaid, wind information was collected from archives at Wunderground and National Data Buoy Center (NDBC):

Arthur formed off the east Florida coast, and meandered in weak steering currents only gradually strengthening. Arthur’s influence on the Florida sea breeze brought isolated tropical storm to severe gusts to coastal areas of east Florida. Deep convection on the south side of Arthur is responsible for near Tropical storm conditions with occasional severe gusts in the northernmost Bahamas.Hurricane Arthur made landfall in North Carolina with 100mph winds. These winds likely occurred in a small area to the east (right) of the track and they weren’t sampled by observation sites. Regardless, at least isolated tropical storm force gusts occurred along the immediate coast from northern South Carolina to southern New Jersey. Tropical storm conditions occurred along Arthur’s track through the Outer Banks; severe gusts occurred just to the left of Arthur’s track – hurricane force gusts (and localized hurricane conditions) to the right of the track. A peak gust of 101mph reported at Cape Lookout, NC. An ocean-side storm surge of 2-4feet occurred to the right of Arthur’s track, and was followed by a sound-side storm surge of 3-5feet as Arthur exited the Outer Banks.A now weakening Hurricane Arthur skirts southeastern Massachussets bringing tropical storm conditions there. Localized severe gusts also occurred, with a gust to 60mph reported on Nantucket. Torrential rains led to flash flooding here. Minor coastal water rises were also observed.